A long-distance scanning laser radar is a large-size space coordinate measuring instrument for realizing scanning measuring of cloud data of three-dimensional points on surfaces of large objects in a size range of 100 m−1 km; and the measured data is used as a basis for subsequent reverse reconstruction of a digital model. The long-distance scanning laser radar belongs to a spherical coordinate measuring system and measures three-dimensional coordinates of a target point through one-dimensional laser distance-measuring and angle measuring in a horizontal direction and a vertical direction, wherein a distance-measuring unit can measure a distance within a range of 1 km and acquires point cloud data by scanning in the horizontal direction and the vertical direction. Three-dimensional coordinate measuring precision is an important indicator of a measuring instrument and is one of core parameters which must be defined after an instrument product is developed. Distribution of measuring errors can fully reflect the measuring precision of the instrument. Therefore, acquisition of the distribution of the measuring errors is of great significance to development of products of a long-distance scanning laser radar instrument.
At present, the space coordinate measuring instruments such as a laser tracker, a total station instrument, etc. with measuring principles similar to that of the long-distance scanning laser radar are usually calibrated by a method of combining the laser interferometer with the long guide rail; and the specific method refers to a literature Calibration Specification for Laser Tracker Three-dimensional Measuring System (JIF1242-2010). A measuring range of the long-distance scanning laser radar reaches 1 km, but the long guide rail with a corresponding size cannot be manufactured, so the instrument cannot be calibrated by the above method. Since a long-distance laser distance-measuring technology is realized based on a principle of pulsed laser flight time, few researchers propose a method for simulating a distance with time to test the distance-measuring error of a pulsed long-distance laser distance measuring instrument in laboratories at present. However, the three-dimensional coordinate measured by the scanning laser radar is a compound parameter of distance-measuring information and two-dimensional angle measuring information, and the three-dimensional coordinate measuring error of the long-distance scanning laser radar cannot be obtained by the above method.